package com.imooc.bigdata.hadoop.hdfs;/**
 * Created by luochangyong on 2019/6/26.
 */

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.*;
import org.apache.hadoop.io.IOUtils;
import org.apache.hadoop.util.Progressable;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import java.io.*;
import java.net.URI;

/**
 * 使用Java API操作HDFS文件系统
 */
public class HDFSApp {
    public static final String HDFS_PATH = "hdfs://hadoop000:8020";
    FileSystem fileSystem = null;
    Configuration configuration = null;

    @Before
    public void setUp() throws Exception {
        System.out.println("----------setUp----------");
        configuration = new Configuration();
        //设置副本数量为1
        configuration.set("dfs.replication", "1");
        /**
         * 构造一个访问指定HDFS系统的客户端对象
         * 第一个参数：HDFS的URI
         * 第二个参数：客户端指定的配置参数
         * 第三个参数：客户端的身份，说白了就是用户名
         */
        fileSystem = FileSystem.get(new URI(HDFS_PATH), configuration, "hadoop");
    }
    /*
     * 创建HDFS文件夹
     */
    @Test
    public void mkdir() throws Exception {
        fileSystem.mkdirs(new Path("/hdfsapi/test"));
    }
    /*
     * 查看HDFS内容
    */
    @Test
    public void text() throws Exception {
        FSDataInputStream in = fileSystem.open(new Path("/README.txt"));
        IOUtils.copyBytes(in, System.out, 1024);
    }
    /*
     * 创建文件
     */
    @Test
    public void create() throws Exception {
        FSDataOutputStream out = fileSystem.create(new Path("/hdfsapi/test/b.txt"));
        out.writeUTF("hello pk replication1");
        out.flush();
        out.close();
    }
    /*
     * 测试文件名更改
     */
    @Test
    public void rename() throws Exception {
        Path oldPath = new Path("/hdfsapi/test/c.txt");
        Path newPath = new Path("/hdfsapi/test/d.txt");
        boolean result = fileSystem.rename(oldPath, newPath);
        System.out.println(result);
    }

    /**
     * 拷贝本地文件到HDFS文件系统
     */
    @Test
    public void copyFromLocalFile() throws Exception {
        Path src = new Path("E:\\logs\\app.log");
        Path dst = new Path("/hdfsapi/test/");
        fileSystem.copyFromLocalFile(src, dst);
    }

    /**
     * 拷贝大文件到HDFS文件系统：带进度条
     */
    @Test
    public void copyFromLocalBigFile() throws Exception {
        InputStream in = new BufferedInputStream(new FileInputStream(new File("E:\\software\\jdk-8u171-windows-x64.exe")));

        FSDataOutputStream out = fileSystem.create(new Path("/hdfsapi/test/jdk.tgz"), new Progressable() {
            @Override
            public void progress() {
                System.out.print(".");
            }
        });

        IOUtils.copyBytes(in, out, 4096);
    }

    /**
     * 拷贝HDFS文件到本地:下载
     */
    @Test
    public void copyToLocalFile() throws Exception {
        Path src = new Path("/NOTICE.txt");
        Path dst = new Path("C:\\Users\\SI-GZ-1114\\Desktop");
        fileSystem.copyToLocalFile(false, src, dst, true);
    }

    /**
     * 查看目标文件夹下的所有文件
     */
    @Test
    public void listFiles() throws Exception {
        FileStatus[] statuses = fileSystem.listStatus(new Path("/hdfsapi/test"));
        for(FileStatus file : statuses){
            String isDir = file.isDirectory() ? "文件夹" : "文件";
            String permission = file.getPermission().toString();
            short replication = file.getReplication();
            long length = file.getLen();
            String path = file.getPath().toString();
            System.out.println(isDir + "\t" + permission + "\t" + replication + "\t" + length + "\t" + path);
        }
    }

    /**
     * 递归查看目标文件夹下的所有文件
     */
    @Test
    public void listFilesResursive() throws Exception {
        RemoteIterator<LocatedFileStatus> files =  fileSystem.listFiles(new Path("/hdfsapi/test"), true);

        while(files.hasNext()) {
            LocatedFileStatus file = files.next();

            String isDir = file.isDirectory() ? "文件夹" : "文件";
            String permission = file.getPermission().toString();
            short replication = file.getReplication();
            long length = file.getLen();
            String path = file.getPath().toString();
            System.out.println(isDir + "\t" + permission + "\t" + replication + "\t" + length + "\t" + path);
        }
    }

    /**
     * 查看文件块信息
     */
    @Test
    public void getFileBlockLocations() throws Exception {
        FileStatus fileStatus = fileSystem.getFileStatus(new Path("/hdfsapi/test/jdk.tgz"));
        BlockLocation[] blocks = fileSystem.getFileBlockLocations(fileStatus, 0, fileStatus.getLen());
        for(BlockLocation block : blocks){
            for(String name : block.getNames()){
                System.out.println(name + ":" + block.getOffset() + ":" + block.getLength() + ":" + block.getHosts()[0]);
            }
        }
    }

    /**
     * 删除文件
     */
    @Test
    public void delete() throws Exception {
        boolean result = fileSystem.delete(new Path("/hdfsapi/test/jdk.tgz"), true);
        System.out.println(result);
    }


    @After
    public void tearDown(){
        configuration = null;
        fileSystem = null;
        System.out.println("-----------tearDown------------");
    }





    /*public static void main(String[] args) throws Exception {
        Configuration configuration = new Configuration();
        FileSystem fileSystem = FileSystem.get(new URI("hdfs://hadoop000:8020"), configuration, "hadoop");

        Path path = new Path("/hdfsapi/test");
        boolean result = fileSystem.mkdirs(path);
        System.out.println(result);
    }*/
}